Apparatus and method for mounting dental casts

ABSTRACT

Apparatus and method for mounting complementary maxillary and mandibular dental casts for display in a desired occluded arrangement within a pair of shell-like bases when the bases are in a prescribed relative position, each base having a cavity and a posterior wall, the posterior wall including an external planar basal surface, an opposite internal planar locator surface parallel to the basal surface and complementary interengagable means on a peripheral edge surface between the basal surface and the locator surface. The dental casts are assembled and temporarily secured together in the occluded arrangement, are each provided with a planar posterior locating surface and then located between confronting bases so as to be juxtaposed with the cavities therein with each posterior locating surface engaging a corresponding complementary locator surface. The basal surfaces of the bases are placed upon a common flat surface and the bases are then moved toward one another to engage the complementary means, thereby bringing the bases into the prescribed relative position while an adhesive medium, placed in each cavity, secures each dental cast to a corresponding base as the bases are moved toward one another.

United States Patent n91 Polanco m1 3,882,602 May 13, 1975 APPARATUS AND METHOD FOR MOUNTING DENTAL CASTS [76] Inventor: Julio R. Polanco. l Harriet Ave.,

Palisades Park, NJ. 07650 [22] Filed: Nov. I3, 1973 [21] Appl No: 4l5,422

Primary lzlrumim'rRobert Peshock Attorney. Agent. or I"irmSamuc|son & Jacob I 57 I ABSTRACT Apparatus and method for mounting complementary maxillary and mandibular dental casts for display in a desired occluded arrangement within a pair of shelllike bases when the bases are in a prescribed relative position. each base having a cavity and a posterior wall. the posterior wall including an external planar basal surface. an opposite internal planar locator surface parallel to the basal surface and complementary interengagable means on a peripheral edge surface between the basal surface and the locator surface. The dental casts are assembled and temporarily secured together in the occluded arrangement. are each provided with a planar posterior locating surface and then located between confronting bases so as to be juxtaposed with the cavities therein with each posterior locating surface engaging a corresponding complementary locator surface. The basal surfaces of the bases are placed upon a common flat surface and the bases are then moved toward one another to engage the complementary means. thereby bringing the bases into the prescribed relative position while an adhesive medium. placed in each cavity. secures each dental cast to a corresponding base as the bases are moved toward one another.

l3 Claims. 13 Drawing Figures 1 APPARATUS AND METHOD FOR MOUNTING DENTAL CASTS The present invention relates generally to mounting dental casts and pertains, more specifically, to apparatus and method for mounting complementary maxillary and mandibular dental casts for display in a desired occluded arrangement.

The making and preparation of dental models is a necessary part of dental and orthodontic procedure where a practitioner wishes to display to a patient the appearance of the patients teeth before and after treatment.

In order to facilitate the mounting of dental casts for such models, preformed bases have been developed which enable dental casts to be mounted properly and in appropriate occlusal alignment with the respective bases in less time and with less difficulty than that encountered with previous equipment and procedures which required difficult, tedious, expensive and timeconsuming molding and finishing operations. However, the use of such preformed bases in making models requires that auxiliary apparatus, in the form of a positioner and a relator, be used to assist in mounting and properly aligning the dental casts relative to the preformed bases. It would be advantageous if the model making procedure could be further simplified and shortened by eliminating the requirement for such auxiliary apparatus in-attaining the desired result.

It is therefore an object of the invention to provide apparatus which enables complementary maxillary and mandibular dental casts to be mounted in preformed bases for display in proper occluded arrangement without inquiring special auxiliary apparatus in addition to the preformed bases themselves.

Another object of the invention is to provide a pair of complementary bases having a configuration which enables them to be used in mounting dental casts in a desired occluded arrangement utilizing a simplified procedure which requires no further apparatus for assuring proper location and alignment of the dental casts relative to the bases.

Still another object of the invention is to provide a simplified, efficient and shorter method for the mounting of complementary dental casts in preformed bases.

A further object of the invention is to provide complementary preformed bases having a configuration including structural features in the bases themselves which enable the appropriate location and alignment of dental casts within the bases and the proper location and alignment of the bases relative to one another.

A still further object of the invention is to provide complementary preformed bases for mounting dental casts, the bases being relatively simple in construction and concomitantly inexpensive to manufacture while being easily used by the practitioner.

The above objects, as well as still further objects and advantages, are attained by the invention which may be described briefly as apparatus for use in mounting complementary maxillary and mandibular dental casts for display in desired occluded arrangement, the dental casts each having a posterior locating surface, the apparatus comprising a pair of bases, each base having a cavity and a posterior wall including an external basal surface and an opposite internal locator surface, and complementary interengagable means on the bases for locating the bases in a prescribed relative position when the complementary means are engaged, each locator surface being complementary to the posterior locating surface of a corresponding dental cast such that the dental casts will be in desired occluded arrangement when the bases are in the prescribed relative position and each dental cast is juxtaposed with the cavity of a base, with the posterior locating surface thereof engaging the internal locator surface of the base.

The invention will be more fully understood, while still further objects and advantages thereof will become apparent in the following detailed description of an embodiment of the invention illustrated in the accompanying drawing, in which:

FIG. 1 is a pl'an view of an upper, or maxillary, base constructed in accordance with the invention;

FIG. 2 is a front end view of the upper base;

FIG. 3 is a side elevational view of the upper base;

FIG. 4 is a longitudinal cross-sectional view taken along line 4-4 of FIG. 1;

FIG. 5 is a plan view of a lower, or mandibular, base constructed in accordance with the invention;

FIG. 6 is a front end view of the lower base;

FIG. 7 is a side elevational view of the lower base;

FIG. 8is a longitudinal cross-sectional view taken along line 8-8 of FIG. 5;

FIG. 9 is an expanded perspective view illustrating the upper and lower bases being utilized in accordance with the method of the invention;

FIG. 10 is a perspective view illustrating a further stage in the method;

FIG. 11 is a longitudinal cross-sectional view, reduced in size, taken along line 11-11 of FIG. 10;

FIG. 12 is a pictorial view of complementary maxillary and mandibular dental casts mounted in corresponding upper and lower bases; and

FIG. 13 is a perspective view of complementary max illary and mandibular dental casts assembled and secured in an occluded arrangement.

Referring now to the drawing, and especially to FIGS. 1 through 8 thereof, apparatus constructed in accordance with the invention is illustrated in the form of an upper, or maxillary, base 20 and a lower, or mandibular, base 22.

Turning first to the upper base 20, as illustrated in FIGS. 1 through 4, base 20 has a shell-like construction which includes a bottom 24, side walls 26, a front or anterior wall 28 and a rear or posterior wall 30, all of which define acavity 32 in the base 20. The side walls 26 and anterior wall 28 extend generally perpendicular to the bottom 24 and are angled relative to one another around the periphery of the base to approximate the contour of the human maxillary dental configuration so that a maxillary dental cast can be received within the base 20, as will be described in detail below.

The posterior wall 30 is provided with an external basal surface 34 which preferably is planar in configuration and generally perpendicular to the bottom 24. An opposite internal locator surface 36 is provided along the interior of the posterior wall and a peripheral edge surface 38 extends between the basal surface 34 and the locator surface 36. The locator surface 36 preferably is planar and extends parallel to the basal surface 34.

The lower base 22, as illustrated in FIGS. 5 through 8, also has a shell-like construction which includes a bottom 40, side walls 42, a front or anterior wall 44 and a rear or posterior wall 46, all of which define a cavity 48 in the base 22. The side walls 42 and anterior wall 44 extend generally perpendicular to the bottom 40 and are angled relative to one another around the periphery of the base to approximate the contour of the human mandibular dental configuration so that a mandibular dental cast can be received within the base 22. as will be described in detail below.

The posterior wall 46 is provided with an external basal surface 50 which preferably is planar in configuration and generally perpendicular to the bottom 40. An opposite internal locator surface 52 is provided along the interior of the posterior wall 46 and a peripheral edge surface 54 extends between the basal surface 50 and the locator surface 52. The locator surface 52 preferably is planar and extends parallel to the basal surface 50.

The bases 20 and 22 are provided with interengagable complementary means which. when engaged with one another. will align and locate the bases in a prescribed position relative to one another. The complementary means are preferably located at the peripheral edge surfaces 38 and 54 of the posterior walls 30 and 46 of bases 20 and 22. respectively. In the illustrated embodiment. the complementary means include projections shown in the form of a pair of keys 56 spaced apart laterally and extending along the peripheral edge surface 38 in a direction generally parallel to the basal surface 34. A pair of recesses shown in the form of key slots 58. complementary to keys 56. are spaced apart laterally and extend along the peripheral edge surface 54 in a direction generally parallel to the basal surface 50.

The keys 56 are located on lobed portions 60 of the posterior wall 30 and thus project away from the bottom 24 well beyond the anterior wall 28 and the major portion of the side walls 26. Likewise. the key slots 58 are located on lobed portions 62 of posterior wall 46 to project away from the bottom 40 well beyond anterior wall 44 and the major portion side walls 42. Keys 56 are tapered slightly toward the tips 64 thereof so that the keys have a slight wedge-shaped configuration. Key slots 58 are likewise tapered toward the roots 66 thereof so that the key slots have a wedge-shaped configuration complementary to the keys 56.

Turning now to FIGS. 9. l and. 11. there is illustrated a method. practiced in accordance with the invention. by which complementary maxillary and mandibular dental casts 70 and 72. respectively. are mounted. respectively. in upper base and lower base Dental casts 70 and 72. which have been fabricated of plaster in a well-known manner. are first assembled and then temporarily secured together in the desired occluded arrangement as by the use of a rubber band 74 which holds the dental casts 70 and 72 in as assembly 75. The assembled dental casts are then each provided with a posterior locating surface 76 and 78. respectively. by grinding. cutting or otherwise removing portions of the dental casts to establish the required loeating surfaces 76 and 78 which are made complementary to locator surfaces 36 and 52 of posterior walls and 46. respectively. In this instance. locating surfaces 76 and 78 are planar surfaces which lnatchthc planar configuration of locator surfaccs 36 and 52.

An adhesive medium 80 is then placed in each cavity 32 and 48 and. if so desired. upon the outside faces 82 and 84 of the dental casts 70 and 72. The bases 20 and 4 22 are placed upon a flat surface 86 which preferably is horizontal and receives complementary basal.sur-, faces 34 and 50 to locate the basal surfacesin a common plane. and the locating surfaces 76 and 78ofthe A occluded assembly 75 are placed upon complementary locator surfaces 36 and 52. The bases 20' and 22 are then moved toward one another bysliding the bases along the flat surface 86 in the directions indicated by the arrows in FIG. 9. thereby engaging the keys 56,

within the key slots 58 as the lobed portions 60and 62 are brought into abutting relationship. The comple.-' mentary wedge-shaped configuration ofthe keys 56 and key slots 58 facilitates the above engagement and aids in bringing the bases 20 and 22 into proper aligned relationship. Once the keys 56 are fully seated within the key slots 58 and the lobed portions 60 and 62 actu face. Lateral alignment of thebases is assured by the engagement of keys 56 with key slots 58. The overall height 88 of the engaged bases is determined by the ex- V tent to which the lobed portions 60 and 62 project away from the bottoms 24 and 40 of the bases- The dental casts and 72. already assembled in the desired occluded arrangement. are located relative to the I bases by the engagement of locating surfaces 76 and 78 with complementary locator surfaces 36 and 52.

The adhesive medium 80 which is placed between 3 the confronting portions of the occluded, assembly and the bases 20 and 22 simultaneously adheres each 3 I, dental cast to its respective base. This the dental casts are located in the desired occludedarrangement when the bases are in the prescribed relative position. As best seen in FIGS. l0 and ll. excess adhesive mediumis ex-. 7 I

uded from between the confronting portions of the occluded assembly 75 and the bases 20 and 22 as the bases are moved toward one another to join the bases with the dental casts. The exuded adhesive medium may be trimmed. after hardening. to finish the model. At the same time. the rubber band 74 may be removed to trimmed so that the upper and lower halves 90 and 92 ofthe completed model may be parted. as illustrated in H6. 12. a Q I Since the dental casts are fabricated of plaster. the adhesive medium preferably isplaster; The bases, 20 and 22 also preferably are fabricated of plaster so that all portions of the model may be finished with the same techniques and the resulting model will have a aesthetically pleasing appearance.

As an alternate to the use of rubberband eating surfaces 76 and 78 established. and the alternate assembly 75a employed in place of assembly 75.,The f halves and 92 of the.completed niodel would then be separated by removing the was bite 94 to release the dental casts from one another. As an alternateto wax I bite 94. a sticky was (not shown) maybeemployed at. spaced locations along the dental casts to secure the,

dental casts together temporarily in occludedarrange ment.

uniform I an... den tal casts 70 and 72 may be secured temporarily in oc- The upper and lower halves 90 and 92 of the completed model are readily brought into the prescribed position wherein the dental casts are displayed in occluded arrangement by locating the basal-surfaces 34 and 50 upon any flat surface and engaging the cone sponding keys 56 and key slots 48. No special relators are necessary to enable the dental practitioner to display the dental casts in a complete model.

It will be seen that the apparatus and method of the invention enables complete dental models to be constructed with simplified mounting of dental casts and without the use of special apparatus in the nature of positioners and relators. The proper alignment and location of the various parts of the model are attained by structural features of the preformed bases and 22 themselves. The fabrication of models in accordance with the invention is done quickly since both the maxi]- lary and mandibular dental casts are mounted to the respective bases 20 and 22 simultaneously and with accuracy.

It is to be understood that the above detailed description of an embodiment of the invention is provided by way of example only. Various details of design and construction may be modified without departing from the true spirit and scope of the invention as set forth in the appended claims.

The embodiments of the invention in which are exelusive property or privelegc is claimed are defined as follows:

1. Apparatus for use in mounting complementary maxillary and mandibular dental casts in desired occluded arrangement, said dental casts each having a planar posterior locating surface, said apparatus comprising:

a pair of shell-like bases, each having a bottom, side walls, an anterior wall and a posterior wall, all integral with the bottom and extending therefrom to establish a cavity, said posterior wall having an external planar surface, an opposite internal locator surface and a peripheral edge surface between said external and internal surfaces; and

complementary interengagable means in the periphcral edge surface of each base, each said complementary means extending in a direction generally parallel to the external planar surface of each base such that upon location of each said planar surface in a common plane and interengagement of said complementary means, the pair of bases will be in a prescribed relative alignment and location;

each said internal locator surface being planar and parallel to the external planar surface of the posterior wall of the corresponding base such that the dental casts will be in said desired occluded arrangement when the bases are in said prescribed relative alignment and location.

2. The invention of claim I wherein the interengagable complementary means include at least one projection in one of said pair of bases and a complementary recess in the other of said pair of bases, said projection and recess each extending in a direction parallel to the external planar surfaces of the bases.

3. The invention ofclaim I wherein the interengagable complementary means include;

a pair of projections in the peripheral edge surface of one of said bases, said projections being spaced laterally and extending in a direction parallel to the external planar surface of said one base; and

a pair ofrecesses in the peripheral edge surface of the other of said bases,"said recesses being spaced laterally and extending in a direction parallel to the external planar surface of said other base.

'4. Theinvention of claim 3 wherein the projections are keys having aslightly wedge-shaped configuration and the recesses are key slots of complementary configuration such that interengagement of the keys in the key slots is attained by relative movement of the bases parallel to the external planar surfaces thereof and the interfitting relationship of the keys and key slots accurately aligns and locates the bases relative to one another.

5. The method of mounting complementary maxillary and mandibular dental casts in complementary bases for display in desired occluded arrangement when the bases are in a prescribed relative position, said bases each including a posterior wall having an external planar basal surface, and an internal planar locator surface parallel to the basal surface, said bases including complementary interengagable means for locating the bases in said prescribed relative position when interengaged with one another, said method comprising:

assembling and temporarily securing the dental casts together in the desired occluded arrangement;

providing each of the dental casts with a planar posterior locating surface complementary to the internal locator surface of a corresponding base;

locating the assembly of dental casts between confronting bases with each posterior locating surface engaging a corresponding complementary locator surface;

placing an adhesive medium between confronting portions of the assembly and the complementary bases;

locating the external basal surfaces of the bases upon a common flat surface; and

moving the bases toward one another and interengaging the complementary means to bring the bases into the prescribed relative position while simultaneously adhering each dental cast of the assembly to a corresponding base.

6. The invention of claim 5 wherein:

each base includes a cavity;

the assembled dental casts, when located between the confronting bases, is juxtaposed with the cavity in each base; and

the adhesive medium is placed within each cavity before the assembly is located between the confronting bases.

7. The invention of claim 6 wherein the bases are moved toward one another by sliding at least one base along the flat surface toward the other base.

8. The invention of claim 7 wherein the flat surface is horizontal and the locator surfaces are horizontal and the assembly rests upon the locator surfaces as the bases are moved toward one another.

9. Apparatus for use in mounting complementary maxillary and mandibular dental casts for display in desired occluded arrangement, said dental casts each having a planar posterior locating surface, said apparatus comprising:

a pair of bases. each base having a cavity and a postcrior wall including an external planar basal surface and an opposite internal planar locator surface parallel to the basal surface; and

complementary interengagable means on the bases for locating the bases in a prescribed relative position when the complementary means are engaged;

each said locator surface being complementary to the posterior locating surface of a corresponding dental cast such that the dental casts will be in said desired occluded arrangement when the bases are in said prescribed relative position and each dental cast is juxtaposed with the cavity of a base, with the posterior locating surface thereof engaging the internal locator surface of the base.

10. The invention of claim 9 wherein the posterior wall of each base includes a peripheral edge surface between the basal surface and the locator surface, and the complementary interengagable means are located in the peripheral edge surfaces.

11. The invention of claim 10 wherein the interengagable complementary means include at least one projection in one of said pair of bases and a complementary recess in the other of said pair of bases, said projection and recess each extending in a direction parallel to the basal surfaces of the bases.

12. The invention of claim l0wherein the interengagable complementary means include:

a pair of projections in the peripheral edge surface of" one of said bases, said projections being spaced laterally and extending ina direction parallel to the basal surface of said one base; and r a pair of recesses in the peripheral edge surface of the a tions are keys having a slightly wedge-shaped. configu:

ration and the recesses are key slots of complementary configuration such that interengagement of the keys in g the key slots is attainedby relative movement of the bases parallel to the basal surfaces thereof and the in? terfitting relationship of the keys and keyslots accu' rately aligns and locates the bases relative to one another. 

1. Apparatus for use in mounting complementary maxillary and mandibular dental casts in desired occluded arrangement, said dental casts each having a planar posterior locating surface, said apparatus comprising: a pair of shell-like bases, each having a bottom, side walls, an anterior wall and a posterior wall, all integral with the bottom and extending therefrom to establish a cavity, said posterior wall having an external planar surface, an opposite internal locator surface and a peripheral edge surface between said external and internal surfaces; and complementary interengagable means in the peripheral edge surface of each base, each said complementary means extending in a direction generally parallel to the external planar surface of each base such that upon location of each said planar surface in a common plane and interengagement of said complementary means, the pair of bases will be in a prescribed relative alignment and location; each said internal locator surface being planar and parallel to the external planar surface of the posterior wall of the corresponding base such that the dental casts will be in said desired occluded arrangement when the bases are in said prescribed relative alignment and location.
 2. The invention of claim 1 wherein the interengagable complementary means include at least one projection in one of said pair of bases and a complementary recess in the other of said pair of bases, said projection and recess each extending in a direction parallel to the external planar surfaces of the bases.
 3. The invention of claim 1 wherein the interengagable complementary means include; a pair of projections in the peripheral edge surface of one of said bases, said projections being spaced laterally and extending in a direction parallel to the external planar surface of said one base; and a pair of recesses in the peripheral edge surface of the other of said bases, said recesses being spaced laterally and extending in a direction parallel to the external planar surface of said other base.
 4. The invention of claim 3 wherein the projections are keys having a slightly wedge-shaped configuration and the recesses are key slots of complementary configuration such that interengagement of the keys in the key slots is attained by relative movement of the bases parallel to the external planar surfaces thereof and the interfitting relationship of the keys and key slots accurately aligns and locates the bases relative to one another.
 5. The method of mounting complementary maxillary and mandibular dental casts in complementary bases for display in desired occluded arrangement when the bases are in a prescribed relative position, said bases each including a posterior wall having an external planar basal surface, and an internal planar locator surface parallel to the basal surface, said bases including complementary interengagable means for locating the bases in said prescribed relative position when interengaged with one another, said method comprising: assembling and temporarily securing the dental casts together in the desired occluded arrangement; providing each of the dental casts with a planar posterior locating surface complementary to the internal locator surface of a corresponding base; locating the assembly of dental casts between confronting bases with each posterior locating surface engaging a corresponding complementary locator surface; placing an adhesive mediuM between confronting portions of the assembly and the complementary bases; locating the external basal surfaces of the bases upon a common flat surface; and moving the bases toward one another and interengaging the complementary means to bring the bases into the prescribed relative position while simultaneously adhering each dental cast of the assembly to a corresponding base.
 6. The invention of claim 5 wherein: each base includes a cavity; the assembled dental casts, when located between the confronting bases, is juxtaposed with the cavity in each base; and the adhesive medium is placed within each cavity before the assembly is located between the confronting bases.
 7. The invention of claim 6 wherein the bases are moved toward one another by sliding at least one base along the flat surface toward the other base.
 8. The invention of claim 7 wherein the flat surface is horizontal and the locator surfaces are horizontal and the assembly rests upon the locator surfaces as the bases are moved toward one another.
 9. Apparatus for use in mounting complementary maxillary and mandibular dental casts for display in desired occluded arrangement, said dental casts each having a planar posterior locating surface, said apparatus comprising: a pair of bases, each base having a cavity and a posterior wall including an external planar basal surface and an opposite internal planar locator surface parallel to the basal surface; and complementary interengagable means on the bases for locating the bases in a prescribed relative position when the complementary means are engaged; each said locator surface being complementary to the posterior locating surface of a corresponding dental cast such that the dental casts will be in said desired occluded arrangement when the bases are in said prescribed relative position and each dental cast is juxtaposed with the cavity of a base, with the posterior locating surface thereof engaging the internal locator surface of the base.
 10. The invention of claim 9 wherein the posterior wall of each base includes a peripheral edge surface between the basal surface and the locator surface, and the complementary interengagable means are located in the peripheral edge surfaces.
 11. The invention of claim 10 wherein the interengagable complementary means include at least one projection in one of said pair of bases and a complementary recess in the other of said pair of bases, said projection and recess each extending in a direction parallel to the basal surfaces of the bases.
 12. The invention of claim 10 wherein the interengagable complementary means include: a pair of projections in the peripheral edge surface of one of said bases, said projections being spaced laterally and extending in a direction parallel to the basal surface of said one base; and a pair of recesses in the peripheral edge surface of the other of said bases, said recesses being spaced laterally and extending in a direction parallel to the basal surface of said other base.
 13. The invention of claim 12 wherein the projections are keys having a slightly wedge-shaped configuration and the recesses are key slots of complementary configuration such that interengagement of the keys in the key slots is attained by relative movement of the bases parallel to the basal surfaces thereof and the interfitting relationship of the keys and key slots accurately aligns and locates the bases relative to one another. 